In the optical fiber field, lightguide fibers are used in optical transmission systems wherein the fibers are connected end-to-end to transfer light or optical energy therebetween. The fibers typically are terminated in connector assemblies which may mate in an adapter which centers the fibers to provide low insertion losses. The connectors are coupled together so that their encapsulated fibers connect end-to-end.
A problem that is encountered when terminating optical fibers in fiber optic connectors, versus terminating electrical conductors in electrical connectors, is that the fiber ends may be damaged by adverse environmental hazards, particularly in the case of an unconnected fiber. In particular, dust and dirt as well as external contact with the fiber may impair the optical transmission capabilities of the fiber.
Consequently, when a fiber optic connector is not in use or is not connected to another connector or associated fiber optic transmission means, it has been proposed to cover the mating end of the connector to prevent dust and other debris from collecting on the exposed end surface of the optical fiber or to prevent external contact therewith. For instance, it is known to provide a dust cover for the end of a fiber optic connector or a housing or body associated with the connector, to be used during transport or storage or at other times when the connector is not in use. One additional very important problem is to protect operator's eyes from dangerous laser beams when the connector is "active".
However, the use of dust covers or end caps present further problems if used in certain applications wherein damage may result from light energy being reflected back toward a fiber as sort of a "feed-back". In other words, if a fiber optic connector is "active" or is transmitting light energy in an unconnected condition, there may be sufficient reflection of the light energy from the dust cover or end cap that the reflected light may damage an active device, such as a laser. Consequently, while the dust cover or end cap may protect the fiber from dust, dirt and damage by external contact, a worse problem may be created by feeding light energy back into the system as a reflection off of the dust cover.
This invention is directed to solving the above problems by providing a movable protective shield which prevents light energy transmitted by an optical fiber from being reflected back toward the fiber and from damaging operator's eyes.